Sound attenuating metal framing member

ABSTRACT

The present invention provides for a metal framing member having improved sound attenuating properties to reduce the sound transmission through a partition wall constructed utilizing the framing members. The framing members have a central web which bridges the interior of a partition wall, attached to either edge of the central wall are upstanding side walls to which the covering material would be attached. The central web is provided a plurality of paired rows of elongated slits oriented along the longitudinal direction of the central web such that there is no uninterrupted line of metal bridging the web from one edge of the web to the other in any transverse direction.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. provisional application Ser. No. 61/360087, filed Jun. 30, 2010.

FIELD OF THE INVENTION

The present invention relates to metal framing members for use in constructing partition walls. In particular, the invention relates to metal framing members which provide for reduced sound transmission through the partition walls.

BACKGROUND OF THE INVENTION

It is common practice in residential and many commercial buildings to separate the various rooms by partition walls to define the space of the room. Such partition walls have in the past been constructed of wood members including top and bottom plates and bridging studs. The use of wood members has its short comings. The supply of lumber is getting scarce and costs have increased during recent years. In addition, wood can warp and go out of shape when it becomes wet as well as being susceptible to fire damage and attack by vermin of various kinds.

In recent years, partition walls framed with sheet metal members have been employed. The use of sheet metal members provides advantages of dimensional stability, ease of manufacturing, and conservation of natural resources, among others. However, metal studs are better conductors of sound then wood and additional measures must be taken to reduce sound transmission through walls.

In partition walls separating units in a multi-unit building, techniques have been developed to reduce the sound transmission through a metal framed partition wall. For example, in some circumstances furring members are installed across the studs of the partition wall and the covering material is attached to this furring member. Another commonly employed technique is the use of double or triple layers of wall board as the covering material for the partition wall. However, both of these techniques increase the cost and time to frame and install the partition walls.

There thus remains a need for metal framing members which can reduce the sound transmission without the use of additional measures.

SUMMARY OF THE INVENTION

The present invention provides for a metal framing member having improved sound attenuating properties to reduce the sound transmission through a partition wall constructed utilizing the framing members. The framing members have a central web which bridges the interior of a partition wall, attached to either edge of the central web are upstanding side walls to which the covering material may be attached. The central web is provided a plurality of paired rows of elongated slits oriented along the longitudinal direction of the central web. The individual rows of slits in the paired rows are offset from one another in the longitudinal direction such that there is no uninterrupted line of metal bridging the web from one edge of the web to the other in any transverse direction.

In an aspect of the invention, the central web is provided with two paired rows of elongated slits, each of the paired rows being adjacent to each of the upstanding side walls.

In a further aspect of the present invention, the slit are longer in the longitudinal direction of the metal stud than the material of the web of the stud between adjacent longitudinally aligned slits.

In yet another aspect of the invention, the slits are at least four times as long as the material between the adjacent longitudinally aligned slits.

In yet another aspect of the invention the central web of the framing member is provided with a main central section bordered by channel shaped ribs adjacent the upstanding side wall. The channel shaped ribs extending longitudinally of the stud. Two paired rows of elongated slits are provided in the main central section of the central web adjacent to each of the longitudinally extending channel shaped ribs.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention are illustrated in the attached drawings in which:

FIG. 1 is a perspective view of a partition wall constructed utilizing a preferred embodiment of the metal framing members of the present invention;

FIG. 2 is a perspective view of a first preferred embodiment of a metal stud of the present invention;

FIG. 3 is an end view of the metal stud of FIG. 2;

FIG. 4 is a side view in cross section of the metal stud of FIG. 2; and

FIG. 5 is an end view in cross section of the metal stud of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to a metal framing member such as studs 10 and tracks 12 utilized in framing partition walls 14 as illustrated in FIG. 1. The partition walls 14 are framed from a metal track 12 forming the top plates 12 a and bottom plates 12 b that are bridged by the parallel spaced apart metal studs 10. The spacing between the metal studs 10 is that typically utilized in construction of walls generally at 16 inches on center although other spacing such as 24 inches on center may be utilized. The studs 10 are attached to the top plate 12 a and bottom plate 12 b through the use of suitable screws 16. Once the partition wall 14 is framed utilizing the studs 10, top plate 12 a and bottom plate 12 b, suitable wall covering material such as wall board 18 is attached to the partition wall utilizing suitable screws 20.

As illustrated in particular in FIGS. 2 to 5, the metal stud 10 has a generally C-shaped rectangular cross section with two parallel spaced apart side walls 22 and a central web 24 bridging the side walls 22. The side walls 22 terminate in inwardly turned ledges 26. The central web 24 may be provided with a main central section 24 a bordered by channel shaped ribs 24 b extending longitudinally of the stud 10. The longitudinal ribs 24 b extend outwardly of the stud 10 and aid in stiffening of the central web of the stud 10.

The main central section 24 a of the web 24 is provided with a plurality of longitudinally extending paired rows of slits 30 which provide the sound attenuating characteristic of the metal framing members of the present invention. As illustrated in the figures, preferably two rows of paired slits 30 are provided adjacent each of the channel shaped ribs 24 b in the main central section 24 a of the central web 24. In framing member not having the channel shaped ribs, it is preferred if the paired rows of slits are provided in the web adjacent each of the upstanding side walls.

The individual rows of slits 30 of the paired rows on each side of the web 24 are offset from one another such that the section of the web 24 a between adjacent individual slits 32 is aligned with the central region of the slit 32 in the adjacent row. In this way, there is no continuous unbroken line of metal in any transverse direction from one edge of the central web 24 to the other. Thus, there is no direct line by which sound may be directly transmitted across the web of the metal stud 10.

In addition, the slits 32 are significantly longer in the longitudinal direction of the metal stud than the material 34 of the web of the stud bridging between adjacent slits 32. Preferably the slits 32 are at least four times as long as the material 34 bridging between the adjacent slits 32. More preferably, the slits 32 are about 2 to 4 inches long and the material of the web 34 between the adjacent slits 32 is about ¼ inch to 1 inch long. Most preferably, the slits 32 are about two inches long and the material 34 between the adjacent slits 32 is about ¼ inch to ½ inch. This also provides for a reduced amount of material through which the sound can transverse the web 24 of the stud 10. By providing the slits 32 as illustrated, the amount of material through which sound can be transmitted across the stud 10 is reduced significantly further aiding in the sound attenuating properties of the metal framing members of the present invention.

As illustrated in the drawings, it is preferred that as the slits 32 are being formed the slits 32 are displaced out of the plane of the web 24 of the metal stud 10. This provides for an air gap 36 between the edge of the slit 32 and the edge of the web 24 of the metal stud 10 further aiding in the sound attenuating properties of the metal framing members of the present invention.

As illustrated in the figures, it is preferred that if in addition to the sound attenuating structures in the metal stud as described that similar structures are also provided in the track 12 forming the top and bottom plates of the metal stud wall.

The sound transmission class (stc) of the stud of the present invention was compared to a standard metal stud in tests conducted utilizing the ASTM standard testing procedure. Walls were constructed utilizing either the metal stud and track of the present invention or a standard metal stud and track. One series of walls had a single layer of drywall applied to each side while another series had a single layer of drywall on one side and a double layer of drywall on the other. The results of the test are shown in Table 1.

TABLE 1 SINGLE LAYER OF SINGLE LAYER ON ONE WALLBOARD ON SIDE, DOUBLE LAYER EACH SIDE ON OTHER SIDE PRIOR ART METAL 44 dB 48 dB STUDS STUDS OF PRESENT 49 dB 54 dB INVENTION

As can be seen from the results of Table 1, the stud of the present invention provides for an improvement of 5 to 6 dB of sound reduction compared to a standard metal stud. This would result in a clearly noticeable reduction in sound transmission with wells constructed with the stud of the present invention as compared to those constructed with the standard metal studs.

The sound attenuating metal framing members of the present invention provide for increased sound attenuating properties compared to a normal metal stud or track, thus greatly enhancing the sound attenuating property of partition walls framed utilizing the framing members of the present invention. This can result in reduced construction costs as additional structures such as additional layers of wall board or furring member may not be required. Alternatively, should additional layers of wall board be installed, sound attenuating properties of a metal partition wall framed with the framing members of the present invention would be enhanced compared to a similar wall arrangement utilizing the prior art studs.

While in the preferred embodiments illustrated, a plurality of rows of slits are illustrated it would be appreciated by those skilled in the art that other arrangements may also be possible without departing from the spirit of the invention. 

1. A metal framing member having improved sound attenuating properties to reduce the sound transmission through a partition wall constructed utilizing the framing members, the framing members comprising a central web for binding the interior of a partition wall, upstanding side walls to which the covering material may be attached, attached to either edge of the central web. The central web being provided with a plurality of rows of elongated slits oriented along the longitudinal direction of the central web, the individual rows of slots being offset from one another in the longitudinal direction such that there is no uninterrupted line of metal bridging the web from one edge of the web to the other in any transverse direction.
 2. A metal framing member as claimed in claim 1 wherein the central web is provided with two individual rows of elongated slits adjacent to each of the upstanding side walls.
 3. A metal framing member as claimed in claim 2 wherein the slits are longer in the longitudinal direction of the metal stud than the material of the web of the stud between adjacent longitudinally aligned slits.
 4. A metal framing member as claimed in claim 3 wherein the slits are at least four times as long as the material between the adjacent longitudinal aligned slits.
 5. A metal framing member as claimed in claim 1 wherein the central web of the framing member is provided with a main central section bordered by channel shaped ribs adjacent the upstanding side walls, the channel shaped ribs extending longitudinally of the stud, and two paired rows of elongated slits are provided in the main central section of the central web adjacent to each of the longitudinally extending channel shaped ribs. 